Direct action latching device with electrical and manual release means



w H. DE BRUIN ETAL March 24, 1970 3,503,021

DIRECT ACTION LATCHING DEVICE WITH ELECTRICAL AND MANUAL RELEASE MEANS 3Sheets-Sheet 1 Filed May 28, 1968 March 24, 1970 H. DE BRUI ETAL-3,503,021

DIRECT ACT LATC G DEV WI ELECTRICAL I AND MANU RELEASE ME Filed May 28,1968 s Sheets-Sheet z IV////// 'III'I March 24, 1970 w. H. DE BRUINETAI- 3,503,021

DIRECT ACTION LATCHING DEVICE WITH ELECTRICAL AND MANUAL RELEASE MEANSFiled May 28, 1968 5 Sheets-Sheet 5 United States Patent 3,503,021DIRECT ACTION LATCHING DEVICE WITH ELEC- TRICAL AND MANUAL RELEASE MEANSWillard H. De Bruin, Milwaukee, and Nobel H. Koertge,

Elm Grove, Wis., assignors to Cutler-Hammer, Inc.,

Milwaukee, Wis., a corporation of Delaware Filed May 28, 1968, Ser. No.732,679 Int. Cl. H011? 7/08 U.S. Cl. 335-254 6 Claims ABSTRACT OF THEDISCLOSURE BACKGROUND OF THE INVENTION 1 This invention relates tolatching devices. In particular this invention relates to latchingdevices that are incorporated with electromagnetic relays, and whichhave electrical and manual release mechanisms.

Latching devices of the type disclosed herein are generally mounted uponthe housing of an electromagnetic relay switching device and have anaxially movable shaft which is coupled to the relay armature. Operationof the relay coil to actuate the relay contacts moves the shaft of thelatching device to a latched position wherein the relay coil may bedeenergized and the latching device will hold the contact mechanismsactuated.

A common construction for such latching mechanisms is exemplified in US.Patent No. 3,101,434 to H. Kitscha. A-plurality1of balls are biased intoa conical housing to wedge against the shaft and prevent movement of theshaft in a reverse direction. In the above patent, a shoulder on theshaft drives the balls along the conical surface until the balls reach apoint therealong of sufiicient width to allow the balls to move outwardto contact the periphery of the shaft above the shoulder. A springmember biases the balls in a reverse direction, toward the narrower partof the conical surface, to wedge against the cylindrical surface of theshaft and prevent its return movement. In this construction consistentlatching positions become difficult to control due to occasionalslippage on the cylindrical surface.

A known variation of the above construction comprises a shaft which hasa pair of base-to-base conical portions substituted for the reduceddiameter portion.

In the variation the balls are initially moved outwardly by one conicalportion and are driven against the bias of the spring to a wider portionof the conical housing by the shoulder formed by the base-to-basejunction on the shaft. When the balls clear the junction, the springmember biases them in a reverse direction toward the narrower portion ofthe' conical housing where they wedge against the shaft at the otherconical portion thereof. The coacting conical surfaces in the latchedposition allow the position of latching to be somewhat bettercontrolled.

One disadvantage to each of the above described constructions is thatthe spring member must overcome the dynamic energy of the balls andreverse their motion in the latching action. While the amount of timeinvolved 3,503,021 Patented Mar. 24, 1970 therein is relatively small,such adverse inertial character- 1st1cs can occasionally result in afailure to latch when the relay coil is pulsed. To provide a positiveand quick acting latching mechanism it is extremely desirable to havethe ball members move directly to the latching positron from a static,or at rest, condition.

SUMMARY OF THE INVENTION It is therefore an object of this invention toprovide an lmproved latching device which is particularly well suitedfor use with an electromagnetic relay device.

It is a further object of this invention to provide an improved latchingdevice which has a quick and' accurate latching action. 4

It is still a further object of this invention to provide an improvedlatching device wherein the latching mechanism moves directly to alatched condition from a static condition.

It is still another object of this invention to provide an improvedlatching device which may be released either electrically ormechanically.

These and other objects and advantages will become more apparent in thefollowing specification and claims when read in conjunction with theaccompanying drawmgs.

DESCRIPTION OF THE DRAWINGS I FIGURE 1 is an elevational view of thelatching device lncorporated with a schematically depicted relay deviceand control circuit therefor;

FIG. 2 is a top plan view of the latching device drawn to an enlargedscale;

FIG. 3 is a longitudinal sectional view of the latching device takenalong line 3-3 of FIG. 2;

FIG. 4 is a cross-sectional view taken along line 44 of FIG. 3;

FIG. 5 is a sectional view similar to FIG. 3 but taken along thepartially rotated line 55 of FIG. 2 and showing the device in thelatched position;

FIG. 6 is a fragmentary sectional view taken substantially along theline 6-6 of FIG. 4 and showing a manual release feature of the device;and

FIG. 7 is a cross-sectional view of the one member of the latchingdevice drawn to a greater scale than the foregoing figures.

DECRIPTION OF THE PREFERRED EMBODIMENT The latching device of thisinvention is indicated in the drawings by the general referencecharacter 2 and is shown in FIG. 1 as being mounted upon anelectromagnetic relay device 4. While the relay device is depictedschematically herein, the same may preferably be of the type disclosedand claimed in a copending application Ser. No. 663,067, filed Aug. 24,1967, and assigned to the and assigned to the assignee of thisinvention.

Relay device -4 comprises an operating coil 6 and a reciprocally movablearmature member 8. Armature 8 is normally biased to a retracted positionrelative to the relay housing by a helical compression spring 10disposed between an-annular flange on armature 8 and a rigid wallportion of the relay housing. Armature 8 is further mechanically coupledto the bridging contacts of a plurality of switch poles 12 of either thenormally open or normally closed types to actuate the switches 12 inresponse to energization or deenergization of the operating coil 6. Theouter end of armature 8 is provided with a coupling member 8a formechanical connection to an operating member of the latching device 2 aswill be described in greater detail hereinafter. Energization ofoperating coil 6 causes armature 8 to be extended, or driven outwardlytoward the latching device 2.

In the preferred relay of the above mentioned copending application themechanical coupling of the armature to the bridging contacts isaccomplished through a push bar member which in turn is coupled to theoperating member of the latch. This construction allows the armature toreturn after deenergization under its own spring pressure, while thelatching device holds the contacts actuated through the push bar.

The latching device 2 responds through a mechanical action to latch thearmature 8 of relay 4 in its extended position after operating coil 6 isdeenergized. Release of the latching device 2 may be accomplished eitherelectrically from some remote point by energizing an electromagniticrlease coil 14 or manually at the relay and latching device location bymovement of a lever 16 in the direction of arrow 18.

The electrically responsive portions of latching device 2 and relaydevice 4 are adapted to be energized by either an AC. or DC. source ofelectrical power having supply lines L1 and L2. The operating coil 6 ofrelay 4 is connected across the lines L1 and L2 in series with anormally open pushbutton switch 20. The twitch poles 12 of relay device4 are connected across the lines L1 and- L2 in series with a load device22 which is to be controlled by the relay 4. The release coil 14 oflatching device 2 is also connected across the lines L1 and L2 in serieswith a normally open pushbutton switch 24 by means of a pair of wiringterminals 26 provided on the coil 14.

The construction of latching device 2 will now be described withparticular reference to FIGS. 1-4 of the drawings. The mechanism of thelatching device is housed in a hollow molded insulating case 28 which isopen to the outer end, or top as viewed in FIGS. 1 and 3. The outerportions of an opposite pair of sidewalls of case 28 have been recessedto expose the release coil 14 and its terminals 26.

The interior configuration of the case 28 varies peripherally at twomajor levels.

A first interior portion betweenthe outer end and a first level 28a isgenerally rectangular uniformly within the sidewalls of the case 28, andcommunicates with the exterior thereof at the recessed sidewalls forcoil 14. A second interior portion extends between the level 28a and alower level 28b. The inner periphery of the second portion may be seenin FIG. 4. A central circular recess 28c is formed in the surface oflower level 28b. Concentric within the recess 280 is a cylindricalopening 28d which extends between the hollow interior of case 28 and thelower exterior surface thereof as viewed in FIG. 3.

The upper portion of case 28 houses the electromagnetic releasecomponents of the latching device 2 and will be described first withparticular reference in FIGS. 3 and 5. A rectangular steel support plate30 rests upon the first level 28a of case 28. Support plate 30* has acentral circular opening therein. A steel collar member 32. is welded tothe underside of support plate 30, the

collar member also having a circular opening therein' which is inalinement with the opening in plate 30. The reduced portion of ashouldered, non-magnetic cylindrical bushing 34 is pressed into thecircular opening of support plate 30'. Bushing 34 serves as a bearingmember for a movable armature assembly as will be described later.

The electromagnetic release coil 14 is of the cast resin type whereinthe exterior may be molded to the desired shape to be readily retainedby the case 28 without undue hardware. The coil rests upon the supportplate 30 and is prevented from rotating by exterior rectangular portionswhich fit within the aforementioned recessed sidewalls of case 2 8.

. A U-shaped magnet frame 36 is disposed over the coil 14, the legs ofwhich depend along the coil within case 28 to rest upon the supportplate 30. A resilient spring washer 38 is disposed between the bightportion of magnet frame 36 and the upper surface of coil 14 to bias thecoil against the support plate. The bight portion of magnet frame 36 isprovided with a central circular opening to receive a reducedcylindrical portion of a depending core piece 40'. The core piece 40 ispreferably secured to the frame 36 by riveting over the protruding endof reduced cylindrical portion. The inner end of core piece 40 isprovided with an annular shading coil 52 which is brazed within acircular groove formed by a steel retaining sleeve 44 pressed over thecore piece 40. Core piece 40 is further provided with an axial boretherethrough to rceive a shaft 46 to be described later.

The support plate 30, coil 14 and magnet frame 36 are all held securely'within the case 28 by a molded insulating cover 48 which is secured tothe case by'four screws 50. Screws 50 pass through clearance openings ateach corner of cover 48, extend along the coil and magnet frame at thefour corners of the upper portion of case 28 and take into alinedthreaded holes28e in surface 28a. of case 28. It may be seen that themagnet frame 36 extends slightly beyond theouter end of case 28 and thatthe cover 48 bears directly upon the frame to hold'the latter securelyupon the support plate 30. i

Latching device 2 is further provided with an arma ture assembly whichcomprises a movable core piece 52, a spring gland 54 and a ball cage 56.A reduced cylindrical end of ball cage 56 extends through a centralcircular opening in spring gland 54 and is press fit into a matingrecess in one end of the movable core piece 52 to trap the spring glandbetween the end of the core piece and the annular shoulder of ball cage56.'

Core piece 52 is received within bushing 34 and the movable assembly isguided for axial movement therein:

A helical compression spring 58 extends between the underside of supportplate 30 and the upper surface of an annular flange of spring gland 54to bias the armature assembly downwardly, or inwardly of the latchingdevice.

The movable core piece 52 and ball cage 56 are provided with alinedaxial bores for receiving the aforementioned shaft 46, the bore in ballcage 56 being of somewhat larger diameter than that of core piece 52.Additionally, ball cage 56 is provided with three equally spaced,radially extending cylindrical apertures 56a (FIG. 4) which extendthrough the sidewall of the 'ball cage. Each aperture 56a is constrictedatthe inner end adjacent the axial central bore of the ball cage byreducing conical portions.

A cylindrical housing member 60 is seated within the recess 28c in lowerlevel surface 28b. Housing 60 has a peripheral groove therein into whichthe inner ends of a pair of diametrically opposed clips 62 extend. Clips62 lie within rectangular recesses 28] (FIGS. 4 and 5) which areslightly lower than the groove in housing 60. A pair of threaded cutscrews 64 extend through clearance openings in clips 62 and are turned.

diameter of the lower portion of ball cage 56. A concentric frustoconical recess portion 60b extends upwardly from bore 60a and flaresoutwardly thereof. Conical portion 60b is relieved near the upper end ofhousing 60 by a concentric cylindrical recess 600. The frusto conicalsurface 60b and cylindrical recess 600 are joined by a concentric secondfrusto conical portion 60d.

Surrounding the exterior of housing member 60 and resting upon thesurface 28b of case 28 is a ring-shaped yoke portion 16a of the manualrelease lever 16. The exteriorly extending portion of lever 16 isconnected to yoke portion 16a by a radially extending dog-leg portion16b(FIG. 4). Diametrically opposed from dog-leg portion 16b on .yoke 16a isan outwardly extending circular tab 16c. Tab 160 is positioned within akey hole recess 28g=in case 28 as seen particularly in FIG. 6, tab 16cserves as the fulcrum for lever 16 when it ismoved in the direction ofarrow 18.

A helical compression-spring 66 extends within the recess 28g to bearbetween the-tab 16c and the support plate 30, thereby affording adownward bias to lever 16; Yoke portion'16a is further provided with apair of upwardly formed bearing portions 16d. These portions arediametrically opposed on the yoke and are on an imaginary centerlinewhich is perpendicular to a similar line between tab .160 and dog-leg16b.

The aforementioned shaft 46 has a slotted outer end for receiveing'theblade of a screw driver or the like and has a threaded shank formed onits inner end. The inner end of shaft '46 is threaded into asecondaryshaft member 68 which has a cylindrical upper portion 68a and alower conical portion 68b. A threaded shank depends from the conical.portion 68b to be threaded into the coupling portion 8a of relay devicearmature 8.

To complete the latching device assembly, three steel ball members 70are inserted within the cylindrical apertures 56a of ball cage 56. Ballmembers 70 are of a. greater diameter than the wall thickness of ballcage 56 and may therefore extend exteriorly of the ball cage 56 andinteriorly of the bore therein simultaneously.

OPERATION The latching device 2 is shown in its unlatched, or releasedposition in FIG. 3. It may be seen therein that the ball members 70,only one of which is shown, are in engagement with the cylindricalsurface portion 68a of shaft 68. The ball members 70 are also resting inthe relieved portion of housing 60, namely on the surface of the conicalportion 60d. It may be noted that the ball members in the releasedposition are very near the point at which the second conical portion 60djoins the conical portion 60b.

Relay device 4 may be operated by depressing the pushbutton 20 toconnect the operating coil 6 to the lines L1 and L2. Energization ofcoil 6 extends armature 8 to actuate the relay switch contacts and drivethe end 8a of the armature upwardly into the latching device 2. Thelatter movement of armature 8 drives shaft 68 and hence shaft 46upwardly, or outwardly of the latching device.

Since the balls.70 are resting against the cylindrical portion 68a ofshaft 68, the latter is allowed upward movement without moving the ballcage 56. As the line formed by the juncture of surfaces 68a and 68bmoves to and beyond the points of tangency on balls 70, the lattercontact the conical surface 68b to move inwardly toward the axis ofshaft 68. Such inward movement of the balls allows them to move out ofthe relieved portion of housing 60 and directly downward into theconical portion 60b under the bias of spring 58. The ball members arethus in engagement with the conical surfaces 60b and 68b and for eachupward increment of movement of shaft 68, the balls 70 move furtherdownward along surface 60b to wedge between the two cooperating conicalsurfaces as shown in FIG. 5 and latch the shaft against reversemovement.

The pushbutton 20 may be released to deenergize the operating coil 6.However, the armature 8 will not be returned by the spring 10 while theshaft 68 is in the latched position and the relay switches willtherefore remain in their actuated condition. As mentioned earlier, thelatching device may be released either electrically or manually. Theelectrical release will be described first.

The pushbutton 24 may be depressed to energize. the release coil 14across the lines L1 and L2. The energized coil establishes a magneticflux field which effects magnetization of the core piece 40. Thelatterin turn exerts an attractive force on the movable core piece tocause the movable armature assembly to move 'upwardly against the biasof spring 58. Ball' cage 56 thereby pulls ball members 70 out oftheconical portion 60b and into the relieved portion of housing 60. As theballs move into the relieved portion of housing 60 they release theconical portion 68b of shaft 68 to allow the latter and armature 8 tomove downward under the bias of spring 10, thereby deactuating the relayswitches 12.

The same release action may be accomplished manually by moving lever 16upwardly in the direction of arrow 18. In FIG. 6 it may be seen thatsuch movement pivots the lever 16 upwardly about the tab 16c to causethe bearing portions 16d to engage the underside of the annular flangeof spring gland 54. The lever movement thereby drives the spring gland54 upwardly against the bias of spring 58 and such movement pulls theball cage 56 and balls 70 out of the latching position.

Thus there is provided a latching device which provides positive andinstantaneous latching of a relay armature or the like wherein thelatching members move directly from a static position to the latchingposition. While but one preferred embodiment is disclosed herein, itshould be apparent that the device is susceptible of variousmodifications without departing from the scope of the appended claims.

We claim:

1. The combination with a rectilinearly movable member having a normalposition and another position displaced from said normal position;

(a) of a latching mechanism for automatically locking said movablemember in said other position when moved thereto and comprising:

(b) means on said movable member providing a cylindrical surface and acontiguous frusto conical surface converging at an angle with the axisof movement of said movable member;

(0) a ball cage concentrically disposed about said means and having atleast one ball mounted in a side operture and engaging with said means;

(d) a fixed, annular member concentrically disposed about said ball cageand having a frusto conical inner recess and a cylindrical recessconnecting with, and having an inner diameter greater than, the majorinner diameter of said frusto conical inner recess;

(e) means biasing said ball cage toward the normal position of saidmovable member so that said ball engages the cylindrical surface of thefirst mentioned means and a portion joining said frusto conical recesswith said cylindrical recess in said annular member; I

(f) said movable member when moved to said other position causing saidball to roll on said cylindrical surface of said first mentioned meansand thereafter upon movement of said ball cage under its bias causingsaid ball to be interposed in wedging relation between the wall of saidfrusto conical recess and the frusto conical surface of said firstmentioned means;

(g) and means for moving said ball cage in a direction opposing itsbiasing means to move said ball out of wedging relation into the spacebetween said cylindrical recess and said cylindrical surface to releasesaid movable member for return movement.

2. The combination according to claim 1 wherein the portion joining saidfrusto conical inner recess with said cylindrical inner recess in saidannular member is a sec-- ond frusto conical inner recess formed at agreater angle to the axis of movement of said movable member than saidfirst mentioned frusto conical inner recess.

r .7 r N 3. The combination according to claim 1 wherein said means formoving said ball cage in a direction opposing its biasing means includesa lever member movable in said direction to engage an extending portionon said ball cage and move the latter in said direction to move saidball out of Wedging relation and effect release of said movable member.

4. The combination according to claim 3 wherein said lever includesayoke portion surrounding said fixed annular member and having a pair ofbearing portions formed at diametrically opposed points thereon, saidbearing portions being offset from the plane of said yoke portion towardsaid extending portion of said ball cage to engage the latter atdiametrically opposed sides of said movable member.

5. The combination according to claim 1 wherein said means for movingsaid ball cage in a direction opposing its biasing means includeselectromagnetic means comprising an electrically energizable coil memberhaving a central opening therein, a stationary core member extendinginto said coil opening, and a movable core member secured to said ballcage and extending into said coil opening toward said stationary coremember and wherein energization of said electrical coil member causesattraction of said movable core member toward said stationary core 8 vmember to move said ball cage in said direction tomove said ball out ofwedging relation and against the bias effect release of said movablemember; p

6. The combination according to claim Spwherein said means for movingsaid ball-cage in a direction opposing its biasing means furtherincludes a lever member movable in said direction independently of saidelectromagnetic means to engage any extending portion on said ball cageand move the latter in said directionto move said ball out of wedgingrelation-and effect release of said movable member.

References Cited UNITED STATES PATENTS 1,326,359 12/1919 Mahoney .Q335-254 3,101,434 8/1963 Kitscha 335-254 3,209,102 9/1965 Boley 335 1703,235,777 2/1966 Hatashita 335-254 G. HARRIS, Primary Examiner U.S. Cl.X.R. 335170

